Egypt's Islamist ex-president was buried in a small family ceremony early on Tuesday a day after he suffered a fatal heart attack in court, his sons said, as supporters posted messages of grief and anger.
“Concerns have been raised regarding the conditions of Mr. Mursi’s detention, including access to adequate medical care, as well as sufficient access to his lawyers and family, during his nearly six years in custody. He also appears to have been held in prolonged solitary confinement," U.N. human rights spokesman Rupert Colville said in a statement.
"The investigation should be carried out by a judicial or other competent authority that is independent of the detaining authority and mandated to conduct prompt, impartial and effective investigations into the circumstances and causes of his death," he said.